The musician has gained new listeners with his diverse 'Historicity' and releases a new album this month. He performs at Pasadena's Levitt Pavilion on Sunday.

Critical acclaim can be a tricky thing. While no musician would reject it, when an album becomes an 800-pound gorilla on year-end best-of lists like Vijay Iyer's knotty yet inviting 2009 album, "Historicity," it's tempting to wonder if there's any downside. Does that kind of reaction go to a guy's head? Does it inspire a musician to venture further out and defy expectations? Or does it prompt a temptation to stick with what's worked in the past?

Speaking by phone from his New York City home, a thoughtful and unaffected Iyer shrugs off such ideas. "The biggest difference it's made is that people are willing to give me gigs now," he said. "Because really the way you reach listeners is by performing…. Most people are not reading 'Downbeat' or 'Jazz Times' and the occasional jazz presence in a national newspaper. It doesn't translate into millions of people knowing about you. It just doesn't."

If those sound like the words of an artist who has been around long enough not to get caught in anyone's hype, it's no accident ("I've been seen as 'emerging' for the last 10 or 15 years," he admits with a laugh). A new solo album due at the end of the month will be Iyer's 11th recording since 1995, and while "Historicity" marked a breakthrough for the 38-year-old pianist, its sales numbers are the sort that Katy Perry might find between her sofa cushions (7,000 copies sold at the time of this writing, according to Nielsen Soundscan). Regardless, if you want to know where jazz is in 2010 and where it's headed, Iyer is among the first musicians to hear.

"He's a great young artist," said trumpeter and CalArts instructor Wadada Leo Smith, who cofounded Chicago's Assn. for the Advancement of Creative Musicians and collaborates with Iyer in Smith's fiery Golden Quartet. "I use the word 'young' not in terms of his music but in terms of his age. He's very bright in terms of musical concepts, philosophies and theorems and things like that."

Slated to perform at Pasadena's Levitt Pavilion this Sunday with his longtime rhythm section of Stephan Crump and Marcus Gilmore, Iyer credits much of this knowledge to "apprenticing" with players such as Smith, the Art Ensemble of Chicago's Roscoe Mitchell and Steve Coleman, champion of the influential improvisational collective M-Base. Such influences point to Iyer's roots in the avant-garde, but his musical approach isn't so easy to pigeonhole.

Though unquestionably steeped in the jazz tradition, Iyer's past collaborations with spoken word artist Mike Ladd and electronic musicians such as Karsh Kale and DJ Spooky reflect his diverse musical palette. On "Historicity," a sinister, thick-grooved cover of M.I.A.'s "Galang" brushes against nimble interpretations of songs by Andrew Hill, Julius Hemphill and keyboardist Ronnie Foster. The latter's "Mystic Brew" is viewed through the lens of a flickering piano lead used by the hip-hop group A Tribe Called Quest, who sampled Foster in 1993. In melding such elements from across the musical spectrum, Iyer shows as little regard for genre and generational divides as most listeners in the iPod age.

"You know, I hope that in doing so people start to accept that there are these other perspectives on [jazz], that one can actually encompass all these things and it's not about this-versus-that, or the past versus the future," Iyer said. "That whole dynamic kind of drives me mad, because that's not ever what this music was. It wasn't ever about tradition versus modernity. It was always about one in the other, or one through the other."

Iyer's new record is a continuation of that philosophy. Though it opens with a disarmingly warm rendering of Michael Jackson's "Human Nature" (a nod to one of his earliest favorites), the album is perhaps Iyer's most tradition-rich recording yet. With a cluster of boldly drawn originals anchoring the record's center, the album is framed by adventurous takes on classics by Thelonious Monk and Duke Ellington. Recorded at the same Bay Area studio Iyer used for his earliest recordings, the album feels like a summation of all that's brought him to this point.

"It's not what I intended to happen…. But when you record these things and listen to the way it is, it's not the album I thought it was," he said. "Basically the album turned into this memoir of sorts."

A self-taught musician born to Indian immigrant parents in upstate New York, Iyer often finds himself branded in the media by his studies outside the music world, which include a master's degree in physics. Though his playing can be undeniably complex, he bristles at hearing words like "mathematical" thrown around in relation to his music. "I mean, 'Giant Steps' is mathematical, Bartok string quartets are mathematical," he said. "I find it more becomes this kind of stereotypical marker like, this Asian nerd who deals with numbers."

Still, as his career has progressed, admirers have surfaced from unlikely places. Last year ESPN approached him to record original music for the cable network, so Iyer headed into the studio with a quartet that included recently signed Blue Note trumpeter Ambrose Akinmusire. The result was funky, muscular and certainly the jazziest collection of "jock jams" likely to be heard between sports highlights.

"So despite this whole reputation as a brainy math-nerd, somehow the suits at ESPN decided that my music was right for the channel," Iyer said, relishing the irony. "I just thought it was funny that when you strip away the signifying cloud you hear something different."